文件下载

.NET下载，有文件源存在。

    public static void DownLoadFile(string fileName, HttpResponse Response, HttpServerUtility Server)
    {
        string path = Server.MapPath("~/UpFiles/" + fileName);
        FileInfo fileInfo = new FileInfo(path);

        //TextWriter writer = new StreamWriter(defultPath);
        //HttpResponse Response = new HttpResponse(writer);

        Response.Clear();

        Response.ClearContent();

        Response.ClearHeaders();

        Response.AppendHeader("Content-Disposition", "attachment; filename="" + Server.UrlEncode(fileName) + """);

        Response.AddHeader("Content-Length", fileInfo.Length.ToString());

        Response.AddHeader("Content-Transfer-Encoding", "binary");

        Response.ContentType = "application/octet-stream";

        Response.ContentEncoding = System.Text.Encoding.UTF8;

        Response.WriteFile(fileInfo.FullName);

        Response.Flush();

        Response.End();
    }

以文本流的方式下载，不存在文件源的方式。

            byte[] tmp = ProServer.XLSIO.ExportExcel(dt, salEnt.NAME);//二进制字符
            string fileName = string.Format("{0}.xls", salEnt.NAME);
            Response.Charset = "UTF-8";
            Response.ContentEncoding = System.Text.Encoding.GetEncoding("UTF-8");
            Response.ContentType = "application/octet-stream";
            Response.AddHeader("Content-Disposition", "attachment; filename=" + Server.UrlEncode(fileName));
            Response.BinaryWrite(tmp);
            Response.Flush();
            Response.End();

MVC下载，存在文件源

        public FileStreamResult DownFile(string fileid)
        {
            using (DBEntities db = new DBEntities())
            {
                int id = Convert.ToInt32(fileid);
                var files = db.PS_FILES.SingleOrDefault(k => k.ID == id);
                string path = Server.MapPath("~/UpFiles/") + files.PATH;
                return File(new FileStream(path, FileMode.Open), "image/jpeg jpeg jpg jpe", files.NAME);
            }
        }

MVC下载，以二进制字符串

        public ActionResult DownF(string fileid)
        {
            using (DBEntities db = new DBEntities())
            {
                int id = Convert.ToInt32(fileid);
                var files = db.PS_FILES.SingleOrDefault(k => k.ID == id);
                string path = Server.MapPath("~/UpFiles/") + files.PATH;
                FileInfo file=new FileInfo(path);
                byte[] buffer;
                using (FileStream fs = file.Open(FileMode.Open))
                {
                    buffer = new byte[fs.Length];
                    fs.Read(buffer, 0, buffer.Length);
                }
                Response.Charset = "UTF-8";
                Response.ContentEncoding = System.Text.Encoding.GetEncoding("UTF-8");
                Response.ContentType = "application/octet-stream";
                Response.AddHeader("Content-Disposition", "attachment; filename=" + Server.UrlEncode(files.PATH));
                Response.BinaryWrite(buffer);
                Response.Flush();
                Response.End();
            }
            return View();
        }